Human body back scattering inspection method and system

Patent metadata

Field	Value
Publication number	US-9651507-B2
Application number	US-201414572528-A
Country	US
Kind code	B2
Filing date	Dec 16, 2014
Priority date	Feb 24, 2014
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A human body back-scattering inspection method and system are discloses. The method includes: obtaining a back-scattering scan image of a human body under inspection; distinguishing a body image from a background image in the back-scattering scan image; and calculating a feature parameter of the background image to determine whether radioactive substance is carried with the human body. With some embodiments of the present disclosure, it is possible to determine whether any radioactive substance is carried with a human body during back-scattering inspection of the human body. In further embodiments of the present disclosure, it is possible to approximately determine which part(s) of the human body carries the radioactive substance. This improves efficiency of inspection.

First claim

What is claimed is:

1. A human body back-scattering inspection method comprising:
obtaining a back-scattering scan image of a human body under inspection;
distinguishing a body image from a background image in the back-scattering scan image; and
calculating a feature parameter of the background image to determine whether a radioactive substance is carried with the human body;
wherein the calculating of the feature parameter of the background image to determine whether the radioactive substance is carried with the human body comprises:
calculating an average luminance value of pixels in the background image; and
determining that the radioactive substance is carried with the human body if the average luminance value is larger than a preset value.

2. The human body back-scattering inspection method according to claim 1 , wherein the step of calculating an average luminance value of pixels in the background image comprises:
integrating luminance data of the background image, and calculating an average of luminance values of the pixels as the average luminance value.

3. The human body back-scattering inspection method according to claim 2 , wherein it is determined that radioactive substance is carried with the human body if the average luminance value is larger than N 0k +n×σ k , wherein N 0k represents a mean value of background luminance, σ k represents a variance of fluctuations in N 0k for a time period, n represents a variance multiplication coefficient, and k represents the number of pixels in the background image.

4. The human body back-scattering inspection method according to claim 1 , further comprising:
dividing the background image into a plurality of parts;
calculating an average luminance value of pixels in each of the parts; and
determining that the radioactive substance is hidden in a part of the body corresponding to the part of the background image having the largest average luminance value.

5. The human body back-scattering inspection method according to claim 1 , wherein a back-scattering detector comprising a plurality of detector modules is used to scan the human body, and the method further comprises:
calculating an average luminance value for each of the detector modules; and
determining the radioactive substance is hidden in a part of the body corresponding to the detector module having the largest average luminance value.

6. The human body back-scattering inspection method according to claim 1 , further comprising:
dividing the background image into a plurality of parts; calculating an average luminance value of pixels in each of the parts; and
determining that the radioactive substance is hidden in parts of the body corresponding to the parts of the background image each having an average luminance value larger than the preset value.

7. The human body back-scattering inspection method according to claim 1 , wherein a back-scattering detector comprising a plurality of detector modules is used to scan the human body, and the method further comprises:
calculating an average luminance value for each of the detector modules; and
determining the radioactive substance is hidden in parts of the body corresponding to the detector modules each having the average luminance value larger than the preset value.

8. A human body back-scattering inspection system comprising:
a ray generator configured to generate a ray beam;
a flying-spot forming device configured to modulate the ray beam and form a flying-spot ray beam;
a back-scattering detector configured to receive a scattered ray generated by irradiating the flying-spot ray beam onto the human body, and generate an electric signal; and
a control and data processing terminal configured to obtain a back-scattering scan image of the human body based on the electric signal, distinguish a body image from a background image in the back-scattering scan image, and calculate a feature parameter of the background image to determine whether radioactive substance is carried with the human body;
wherein the control and data processing terminal calculates an average luminance value of pixels in the background image, and determines that the radioactive substance is carried with the human body if the average luminance value is larger than a preset value.

9. The human body back-scattering inspection system according to claim 8 , wherein the control and data processing terminal integrates luminance data of the background image, and calculate an average of luminance values of the pixels as the average luminance value.

10. The human body back-scattering inspection system according to claim 9 , wherein the control and data processing terminal determines that radioactive substance is carried with the human body if the average luminance value is larger than N 0k +n×σ k , wherein N 0k represents a mean value of background luminance, σ k represents a variance of fluctuations in N 0k for a time period, n represents a variance multiplication coefficient, and k represents the number of pixels in the background image.

11. The human body back-scattering inspection system according to claim 8 , wherein the control and data processing terminal divides the background image into a plurality of parts, calculates an average luminance value of pixels in each of the parts, and determines that the radioactive substance is hidden in a part of the body corresponding to the part of the background image having the largest average luminance value.

12. The human body back-scattering inspection system according to claim 8 , wherein the back-scattering detector comprises a plurality of detector modules, and
the control and data processing terminal calculates an average luminance value for each of the detector modules, and determines the radioactive substance is hidden in a part of the body corresponding to the detector module having the largest average luminance value.

13. The human body back-scattering inspection system according to claim 8 , wherein the control and data processing terminal divides the background image into a plurality of parts, calculates an average luminance value of pixels in each of the parts, and determines that the radioactive substance is hidden in parts of the body corresponding to the parts of the background image each having an average luminance value larger than the preset value.

14. The human body back-scattering inspection system according to claim 8 , wherein the back-scattering detector comprises a plurality of detector modules, and
the control and data processing terminal calculates an average luminance value for each of the detector modules, and determines the radioactive substance is hidden in parts of the body corresponding to the detector modules each having the average luminance value larger than the preset value.

Assignees

• Univ Tsinghua
• Nuctech Co Ltd

Inventors

• Chen Zhiqiang
• Zhao Ziran
• Li Yuanjing
• Wu Wanlong
• Ruan Ming
• Zhang Li
• Jin Yingkang
• Tang Le
• Ding Xianli
• Zhu Chenguang

Classifications

• G01T1/167 Primary

  Measuring radioactive content of objects, e.g. contamination (whole body counters G01T1/163) · CPC title

• G01N23/203 Primary

  Measuring back scattering · CPC title

• G01V5/0025

  Physics · mapped topic

• G01V5/0091

  Physics · mapped topic

• G01V5/222

  measuring scattered radiation · CPC title